Treatment efficacy of ramucirumab-based chemotherapy in patients with alpha-fetoprotein producing gastric cancer (AFPGC).

Abstract

389 Background: AFPGC is an aggressive subgroup of gastric cancer and is associated with a worsened survival because of a high incidence of liver metastasis. Ramucirumab-based chemotherapy is the standard treatment as a second line in advanced gastric cancer. Recently ramucirumab has showed survival benefit in hepatocellular carcinoma, but only those with higher AFP levels. However, the efficacy of ramucirumab in AFPGC is unknown. Methods: We retrospectively assessed 283 patients who received paclitaxel or nab-paclitaxel combined with ramucirumab between July 2015 and December 2018. AFPGC was defined when serum AFP levels were elevated and correlated with the disease state during treatment. Non-AFPGC was defined when serum AFP levels were normal when diagnosed. Other patients were excluded. Patients’ demographics, progression-free survival (PFS), overall survival (OS) and objective response rates (ORR) were compared between the two groups. Results: Among the 283 patients, 24 patients were AFPGC and 189 patients were non-AFPGC. AFPGC was associated with high incidences of intestinal histology (46%) and liver metastasis (63%), while AFPGC was associated with a low incidence of peritoneal metastasis (21%), compared with non-AFPGC. There was no significant difference in PFS and OS between the two groups. Median PFS were 5.4 (95%CI 3.6-6.7) months in AFPGC and 4.1 (3.7-5.1) months in non-AFPGC (HR 0.93 95%CI 0.60-1.46, p = 0.788), respectively. Median OS were 19.0 (95%CI 13.2-NA) months in AFPGC and 19.3 (17.9-20.1) months in non-AFPGC (HR 1.21 95%CI 0.70-2.10, p = 0.494), respectively. Regarding with ORR, AFPGC showed higher ORR with 52.6% (95%CI 30.2-75.1), while 37.3% (95%CI 26.4-48.3) in non-AFPGC (p = 0.296), although this was not statistically significant. Conclusions: Ramucirumab showed comparable survival and higher ORR in AFPGC than in non-AFPGC. Considering the generally poor prognosis of AFPGC, it is speculated that ramucirumab may have compensated for disadvantage in survival.